The invention relates to a sealing arrangement for a piston pump, particularly a high or maximum pressure pump. As a means for sealing the clearance between a reciprocating plunger and cylinder, the improved seal arrangement is comprised of at least two sets of seals disposed one behind the other.
For packing the sealing clearance between plunger and cylinder in high or maximum pressure pumps relatively long seals are necessary. In this connection, and particularly as regards the portion of the seal which is situated furthest from the pressure medium, the danger of running dry arises, as in this area unsatisfactory lubrication conditions prevail. In principle, it is furthermore a problem to keep the sealing clearance constant, as the resilient cylinder expands on the delivery stroke of the plunger and contracts again on the suction stroke.
A solution as to how to keep the sealing clearance constant is described in the published West German Pat. No. P 28 46 172.5 according to which specially constructed floatingly mounted sealing sleeves are disposed one behind the other in the sealing clearance. However, this means that no seals as normally commercially available can be used.